outbound1.usgov.questionmark.com has no MX records.
Question and response
Question
dig ausgv-prdout1.usgovvirginia.cloudapp.usgovcloudapi.net. MX
Answer
The response has no answer records.
Authority
usgovvirginia.cloudapp.usgovcloudapi.net. 60 SOA ns1-02.azuregov-dns.us. msnhst.microsoft.com. 1 900 300 604800 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0